Antioxidant defence-related genetic variants are not associated with higher risk of secondary thyroid carcinoma after treatment for childhood cancer

  • Ana Lina Vodušek Institute of Oncology Ljubljana, Zaloška 2, 1000 Ljubljana, Slovenia
  • Katja Goričar Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
  • Barbara Gazić Institute of Oncology Ljubljana, Zaloška 2, 1000 Ljubljana, Slovenia
  • Vita Dolžan Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
  • Janez Jazbec University Children’s Hospital, Bohoričeva 20, 1525 Ljubljana

Abstract

Background. Secondary thyroid carcinoma is one of the most common neoplasms after childhood cancer treatment. Thyroid gland is very sensitive to the carcinogenic effect of ionizing radiation, especially in children. Imbalance between pro- and anti-oxidant factors may play a role in thyroid carcinogenesis. Our study aimed to assess the relationship between genetic variability of antioxidant defence-related genes and the risk of secondary thyroid cancer after treatment for childhood cancer.

Patients and methods. In a retrospective study, patients with secondary thyroid cancer (cases) and controls matched for age, gender, and primary diagnosis were genotyped for SOD2 p.Ala16Val, CAT c.-262C>T, GPX1 p.Pro200Leu, GSTP1 p.Ile105Val, GSTP1 p.Ala114Val and GSTM1 and GSTT1 deletions. The influence of polymorphisms on occurrence of secondary cancer was examined by McNemar test and Cox proportional hazards model.

Results. Between 1960 and 2006 a total of 2641 patients were diagnosed with primary cancer before the age of 21 years in Slovenia. Among them 155 developed a secondary neoplasm, 28 of which were secondary thyroid carcinomas. No significant differences in the genotype frequency distribution were observed between cases and controls. Additionally we observed no significant influence of investigated polymorphisms on time to the development of secondary thyroid cancer.

Conclusion. We observed no association of polymorphisms in antioxidant genes with the risk for secondary thyroid carcinoma after treatment for childhood cancer. However, secondary thyroid carcinoma is one of the most common secondary cancers after treatment for childhood cancer and the lifelong follow up of patients with childhood cancer is of utmost importance.

Author Biographies

Ana Lina Vodušek, Institute of Oncology Ljubljana, Zaloška 2, 1000 Ljubljana, Slovenia

Department of Radiation Oncology

Ana Lina Vodušek, MD

Katja Goričar, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia

Pharmacogenetics Laboratory

Katja Goričar, PhD

Barbara Gazić, Institute of Oncology Ljubljana, Zaloška 2, 1000 Ljubljana, Slovenia

Department of Pathology

Barbara Gazić, PhD, MD

Vita Dolžan, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia

Pharmacogenetics Laboratory

Prof. Vita Dolžan, PhD, MD

Janez Jazbec, University Children’s Hospital, Bohoričeva 20, 1525 Ljubljana

Department of Hematology and Oncology

assoc. prof. Janez Jazbec, PhD, MD

Published
2016-02-09
How to Cite
Vodušek, A. L., Goričar, K., Gazić, B., Dolžan, V., & Jazbec, J. (2016). Antioxidant defence-related genetic variants are not associated with higher risk of secondary thyroid carcinoma after treatment for childhood cancer. Radiology and Oncology, 50(1). Retrieved from https://www.radioloncol.com/index.php/ro/article/view/2343
Section
Experimental oncology